Consolidated Balance Sheet (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Statement of Financial Position [Abstract]
Investment securities, available for sale, amortized cost	$ 19,054	$ 10,691
Investment securities, held to maturity, fair value	12,955	14,308
Equity and other securities, cost	$ 1,007	$ 1,125
Preferred stock, par value (in USD per share)	$ 1.00
Preferred stock, shares authorized (in shares)	20,000,000
Common stock, par value (in USD per share)	$ 0.50	$ 0.50
Common stock, shares authorized (in shares)	250,000,000	250,000,000
Common stock, shares issued (in shares)	179,436,779	179,436,779
Common stock issuable (in shares)	11,642	12,217
Treasury stock, common shares (in shares)	13,922,820	13,300,298